Parasomnias are the class of sleep disorders associated with abnormal sleeptime behavior. One of the most common examples of parasomnia, for example, is somnambulism (better known as sleepwalking).

But as far as parasomnias go, sleepwalking is actually fairly run-of-the mill. Here are ten examples of some of the most interesting, dangerous, and peculiar cases of parasomnia in recent history.

10. Somniloquy
You've heard of people talking in their sleep? Technically that's called "somniloquy," and while most of us have propbably heard someone murmur incoherently a time or two, the fact is that some people are much more prolific sleep-orators than others.

Take New York City songwriter Dion McGregor, for example. When McGregor slept, he would regularly give play-by-play accounts of his dreams at a conversational volume. He did this so often that in the 1960s, his roommate recorded McGregor's sleeptime narrations and released them on an album titled The Dream World of Dion McGregor (He Talks In His Sleep). Featured here is a song off the album by the name of "Peony." (You can find more of McGregor's dream recordings on Myspace and YouTube. Fair warning: dreams are often full of graphic and NSFW content; the same can be said for many of McGregor's descriptions.)

9. Get Divorced
Somniloquy is rarely much of an issue for its sufferers, especially because coherent sleep-talkers are so uncommon. But problems can arise when intelligible somniloquies fall upon the wrong ears — your spouse's for example. In fact, in 2006, a Muslim couple was ordered to separate when the husband allegedly uttered "talaq" three times in his sleep (In Arabic, "talaq" means divorce; uttering it three times in a row is, in some Islamic traditions, grounds for dissolution of a marriage).

8. Murder your mother-in-law
By the year 2000, there had been an estimated 68 cases of homicide-while-sleepwalking reported worldwide. One of the most notable took place in 1987, when 23-year-old Ken Parks rolled out of bed, got in his car, drove to his inlaws' house, strangled his father-in-law and stabbed his mother-in-law to death before driving himself to the police station. There, he declared: "I think I have killed some people... my hands." A jury later found him not guilty.

7. Cheat on a diet
Doctors call this form of parasomnia Nocturnal Sleep-Related Eating Disorder (or NS-RED). Translation: sufferers binge eat in their sleep. This is different from night eating syndrome (NES), where people regularly consume large meals late at night. The difference, of course, is that NES sufferers are actually awake for their meals. In contrast, NS-RED sufferers have been known to amble into their kitchens, prepare a sandwich, eat it, and return to bed, all in their sleep — only to awake hours later, stuffed, and without any recollection of their midnight.

Worst of all? According to this video, sleep-eaters tend to prefer outrageously unhealthy foods that most people would probably never consumer on their own — like mayonnaise, straight from the jar.

6. Cook a meal
Unless, of course, you've been prescribed Ambien, in which case there's a decent shot of you putting down the tub of mayo in favor of an actual meal. According to the FDA, patients prescribed the popular sleeping pill have been known to actually prepare meals (albeit sloppily), and even use the microwave.

5. Cheat on a significant other
The symptoms of sleepsex (aka sexsomnia) can present in various forms. Sometimes the sexual activity is limited to self-pleasure, but it often involves other parties, as well. In the most extreme cases, it can lead to sex with strangers, and even sexual assault and rape.

The [cause] of this parasomnia is not yet elucidated and most afflicted individuals do not seek therapeutic intervention, probably due to ignorance of the condition or embarrassment. Atypical sexual behavior during sleep has rarely been documented; however, because of recent case reports within forensic contexts, more attention has been paid to the matter. Although there has been increased interest in all aspects of sleep-generating mechanisms and male sexual dysfunction, comprehension of sleep disorders as they relate to sexual behavior is still unclear.

Sexsomnia, along with murder, is probably one of the most psychologically damaging forms of parasomnia, not only due to the emotional impact it can have on the sufferers and the people they interact with during an episode of sleep sex, but for its potential for abuse, as well. The press is riddled with examples of people being acquitted of rape charges on account of their sexsomnia, but confirming these cases can be incredibly difficult. [Photograph via Shutterstock]

4. Hurl yourself from a window (and survive the fall)
That's right — if you're a sleepwalker, there's a decent chance that you'll subject yourself to self-defenestration. Back in 2007, a teenager in Germany managed to climb out of a fourth-floor window in his sleep. Incredibly, he not only survived the fall, he actually sustained relatively minor injuries — a broken arm and leg (it bears mentioning that he remained asleep throughout the entire accident).

And it turns out that if you're going to throw yourself out a window, you might want to be asleep for it, anyway; the fact the teenager was asleep may have saved him from a much more serious injury, or even death. Consider this: if you find yourself in a free-fall sans chute, experts recommend not panicking and letting your muscles relax. The reasoning behind this is that more limp you are, the less impact the fall will have on your bones. But just imagine trying to be reasonable and relaxed while falling from a fourth-floor window, and it's easy to see how being asleep could actually be beneficial once you've stepped out the window. [Picture via]

2. Conduct an orchestra
It's not uncommon for passions from a sleepwalker's waking life to cross over into their nighttime antics. Case in point: Harry F. Rosenthal. An Associated Press reporter by day, Rosenthal is also a classical music enthusiast, a part-time maestro, and a lifelong sleepwalker. Bring them all together and you get news like this from the University of Pennsylvania School of Medicine:

[Rosenthal's sleepwalking is] also at times a source of amusement for his wife, Naidene. For example, one night she heard strange noises coming from the bedroom where he was sleeping. "There was Harry sitting up in bed conducting an orchestra — and he was also vocalizing all the instruments. I brought our kids in to see, too and I even made a tape recording of it."

Rosenthal says he has no memory of his stint as a conductor "or playing all the parts in the orchestra," and he says that is usually the case with his nocturnal adventures. He knows they happen because he wakes up in strange places or he is told about his antics by witnesses. "It's usually just embarrassing," he says.

1. Draw a "masterpiece"
The thing about Rosenthal's nighttime conducting sessions is that he was actually really into classical music; the man was actually known to step in as a conductor in a pinch. Some people, however, engage in sleeptime behavior that has no basis in their waking-life.

Among the most notable examples is Lee Hadwin. A Nurse by day, Hadwin becomes a gifted artist in his sleep, using charcoal pencils and huge sheets of paper to produce "strange and fantastical works of art."

Strangest of all, Hadwin says, "is that if I lift a pencil and try to draw when I'm awake, I'm unable to do even a simple sketch." Videos of Hadwin show that his nighttime sessions last between 20 and 90 minutes, and are characterized by long stretches of intense, high-speed drawing. When he awakes, he claims that he feels physically and mentally drained.

"Of course there are sceptics out there," he explains in this interview with The Daily Mail. "It's frustrating because I can't prove that I'm real, beyond showing video footage of my sleepwalking self at work." He's also told the BBC that he has no real interest in art. "That's one of the reasons I'm keen to be investigated by sleep experts." [Picture via]